"One XNOOP in 100 loops will make Emacs terminate"

05/06/2016

/* On some systems, an X bug causes Emacs to get no more events
when the window is destroyed. Detect that. (1994.) */if(!event_found){/* Emacs and the X Server eats up CPU time if XNoOp is done every time.
One XNOOP in 100 loops will make Emacs terminate.
B. Bretthauer, 1994 */x_noop_count++;if(x_noop_count>=100){x_noop_count=0;if(next_noop_dpyinfo==0)next_noop_dpyinfo=x_display_list;XNoOp(next_noop_dpyinfo->display);/* Each time we get here, cycle through the displays now open. */next_noop_dpyinfo=next_noop_dpyinfo->next;}}